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2004 gmc envoy_sle_xl
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I have an 04 envoy and several months ago it threw a p0410 error. I took it in for service and they took off the hose and said the pump was full of water. I didn't replace it yet, but now inspection is coming up and I need to get it taken care of.

1) Is it easy to replace for a non-professional?

2) A salvage yard has 2003 and 2005 envoys, (not a 2004, my year). Do you know if either of these years are compatible? The parts department at the dealer wouldn't give a part number. This would save me over $250.

Thanks in advance
 

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2004 gmc
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Some folks have blown it out with compressed air and found it recovers. Any way you can jump the relay with a 12V wire and see if you can force it to spin? Any experience with wiring like that?

The pump itself is GM 12574379 (ACDelco #215-454). $350 or so list price. $200 at parts4chevys.com. I see two on Ebay now, $150 and $175. They should also be available from junkyards - check www.car-parts.com



AFAIK, all years use the same one.

 

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Just happened to find this thread, thanks for the info Roadie :tiphat

Mine keeps intermittently acting up ever since I bashed the general area during the river crossing at TECORE.

The relay got knocked off its perch so I cleaned it out and put some dielectric grease in there. Now the error comes up every 4 - 8 starts.

I will try the compressed air first.


AG
 

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Discussion Starter #4
This was very helpful.

The water was removed from it, the error cleared, but the error would come back in a few days after I cleared it.

Don't know how to jump the relay.. As for a replacement part, a local salvage yard has one off an '05 for $100. It seems as easy as removing the old one, and popping on the new one. Am I safe to assume this? How long should it take a backyard mechanic like myself?

Thanks!
 

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Just happened to find this thread, thanks for the info Roadie
Glad to help. Somehow I ended up being the P0410 specialist as well as the 4WD system. :confused:

How long should it take a backyard mechanic like myself?
Depends entirely on how corroded the bolts are. You might start by spraying them with PB Blaster for a few days before you do the replacement. (WD40 is NOT a penetrating oil, although it sometimes masquerades as such during full moons.) I'd guess an hour max.

Inspect the relay well when you're under there also, assuming the junkyard one doesn't have a new relay. It might.

And then you'll have to listen carefully for the next few cold starts to make sure the pump does its thing. It may take 3-5 good cold starts over a few days to make the SES light go out. It's not an instant fix when it comes to this emissions-related code.
 

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If I install it, and confirm it is working...then wipe the error with my computer to turn out the SES light, do you think I am in good shape for an emission test?
 

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No. Emissions testing can't be tricked by just clearing the code and then getting in there quickly for the test. Or else everybody would cheat like that. It requires (I think) at least three successful drive cycles (meaning cold start, warm up, drive around for some minimum time, then stop and cool off) with that diagnostic passing. That's why I said it may take a few days. Are you doing this now because it's overdue already? :worried:
 

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I am not overdue yet...I do want to get in the shop for inspection by Friday because I will be out for the remainder of the month.

Just to recap, so I understand what you are saying...

So the diagnostic cycles you mentioned...these are the ones performed by the computer within the car, not the shop, correct?

After the part is installed (tonight), i clear the code, then I drive it a couple of days, theoretically hitting the cold start, warm start, and etc...I can take it in on Thurs/Friday?

Sorry for the probing on this, I just want to make sure I am doing this the right way.

Thanks!
 

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The diagnostics are scheduled by the PCM, yes. The air pump will always run on a cold start, and if you let it finish (40-60 seconds) before driving away, it will be the happiest. If you drive off while the pump is running (first 10-15 seconds) that diagnostic will fail, and it will try again later while you're driving along (5-20 miles later, under certain conditions) and the current draw of the pump (25-30 amps!) has been blamed for intermittent voltage drooping and nighttime light dimming.

So your best bet is a cold start, don't drive off right away, and make sure you can hear the pump spinning after you replace it. Cold start for this purpose is defined as an ECT between 37 and 122 degrees F)
 

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Discussion Starter #10
When do you recommend clearing the code after it is installed? Does it even matter?
 

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Cool...I will report back after we so how it goes.

Thanks for laying it out for me. Especially how it does its self diagnostics.
 

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Relay and pump

First, Roadie thanks for all the posts on this topic I've learned a lot about this issue and am going to try and tackle it myself, however, quick question, if I do hear the air pump running on a cold start does this mean the relay is OK or does it still need to be tested.

Also if the pump runs does that also mean all the fuses are OK as well.

Thanks!:D
 

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There are two parts of the system. If you can hear the turbine air pump running, then its fuse and locally-mounted relay are OK. The pump sends air to a solenoid-controlled valve on the exhaust manifold (trace the hose) and if it's OK, then if you remove the hose before a cold start, you hear exhaust noises out of it for the same few seconds that the pump runs. This solenoid valve can get stuck shut with exhaust crud, and removing it for a cleaning often works as a free fix.

The solenoid valve (search for previous discussions of it with pictures) also has a fuse and a relay in the front fuse block.
 

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Discussion Starter #15
OK...I replaced the pump with the new one from the salvage yard. It also had a relay attached to it as well.

The old one was filled with water again.

I started it up, but it may not have been a cold enough start. When does the pump run exactly so I can ensure the pump is turning. Only on a cold start?

Another tidbit, after letting it run for a bit, i pulled off the inlet hose from the pump housing (the smaller hose). It seemed like condensation was developing. Not sure why exactly. Is this normal.

I just hope that it would not cause the pump to fail again.

Thanks Rodie!
 

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I've never had to replace my own pump. I just have a shop manual and look stuff up a lot. ;)

So I don't know the normal condition of the hoses water-wise, but I do know a 25-30 Amp turbine pump is going to blow a LOT of air through those hoses when it runs, and that should clean out normal condensation collection.

If the ECT is between 37 and 122 degrees F, the pump should run for 15-25 seconds after you start the engine, and don't drive off. Bend down and listen, or pull the outlet hose off the exhaust manifold solenoid valve (#2 in the drawing) and see if air blows out there, and you can hear exhaust noises for those 15-25 seconds out of the solenoid valve.

 

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Discussion Starter #17
Here's the update for today.

I couldn't here the pump after I installed it, because I think it was above 122 F.

After letting sit all night to cool below that temperature, I started it and heard/felt the pump turning (sounded like a mini-jet engine and when I put my hand on the hose, you could feel the air rushing through it). I did this 3 times and the SES light turned off on its own. There was still a code (from the error prior to replacing the pump) in the OBD computer, that I wiped out.

I think I am an good shape. I will go out mid day to start it and take it for a ride, then do the same to get home. This would make 3 complete "trip" cycles to get me in the clear for inspection.

Sound reasonable to you, roadie?

Thanks again for your prompt responses and in-depth help!
 

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Hi Roadie, ever think about starting a pay site for fixing P0410 :hail:

Ok, the pump runs and I disconnected the hose into the solenoid / check valve and air is pumping out it forcefully and I get the exhaust sound from the solenoid. I didn't check the suction of the hose back to the air pump but can I assume it is fine since the above worked? If yes I guess the next troubleshoot is the stuck valve. So I am trying to remove it.

The problem is the 3 philips screws holding it together are updside down:duh: so I bought a little ratchet set with screw heads and I can get the first two but not the screw closest to the windshield but I will keep trying without stripping it. So when I get this part off I should have access to the area where I can use carb cleaner to try and get the valve to work I am assuming....

Learning every step here and for a novice like me I must admit pretty exciting.

Thanks
 

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If yes I guess the next troubleshoot is the stuck valve.
If you hear exhaust sounds escaping from the solenoid valve when the pump is running, what makes you think it's stuck? That's what you should be hearing. Unless you get the noise all the time, in which case it's stuck open.
 
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